Therapeutic effect of iturin A on <i>Candida albicans</i> oral infection and its pathogenic factors

Abstract

<i>Candida albicans</i> is responsible for conditions ranging from superficial infections such as oral or vaginal candidiasis to potentially fatal systemic infections. It produces pathogenic factors contributing to its virulence. Iturin A, a lipopeptide derived from <i>Bacillus</i> sp., exhibits a significant inhibitory effect against <i>C. albicans</i>. However, its exact mechanism in mitigating the pathogenic factors of <i>C. albicans</i> remains to be elucidated. This study aimed to explore the influence of iturin A on several pathogenic attributes of <i>C. albicans</i>, including hypha formation, cell membrane permeability, cell adhesion, biofilm formation, and therapeutic efficacy in an oral <i>C. albicans</i> infection model in mice. The minimal inhibitory concentration of iturin A against <i>C. albicans</i> was determined to be 25 µg/mL in both YEPD and RPMI-1640 media. Iturin A effectively inhibited <i>C. albicans</i> hyphal formation, decreased cell viability within biofilms, enhanced cell membrane permeability, and disrupted cell adhesion <i>in vitro</i>. Nonetheless, iturin A did not significantly affect the phospholipase activity or hydrophobicity of <i>C. albicans</i>. A comparative study with nystatin demonstrated the superior therapeutic efficacy of iturin A in a mouse model of oral <i>C. albicans</i> infection, significantly decreasing <i>C. albicans</i> count and inhibiting both fungal hypha formation and tongue surface adhesion. High-dose iturin A treatment (25 µg/mL) in mice had no significant effects on blood indices, tongue condition, or body weight, indicating the potential for iturin A in managing oral infections. This study confirmed the therapeutic potential of iturin A and provided valuable insights for developing effective antifungal therapies targeting <i>C. albicans</i> pathogenic factors.